1. Field of the Invention
The invention relates to a β-Ga2O3-based single crystal substrate.
2. Description of the Related Art
To grow a β-Ga2O3 single crystal by EFG method is known (see, e.g., a non-patent literature: “Growth of β-Ga2O3 Single Crystals by the Edge-Defined Film Fed Growth Method” by Hideo Aida, Kengo Nishiguchi, Hidetoshi Takeda, Natsuko Aota, Kazuhiko Sunakawa, Yoichi Yaguchi, Japanese Journal of Applied Physics, Volume 47, No. 11, pp. 8506-8509 (2008)). The non-patent literature discloses a method that a β-Ga2O3 single crystal is grown while gradually broadening a width thereof from a contact portion with a seed crystal toward the bottom, i.e., while broadening the shoulder in a width direction, thereby allowing a plate-shaped crystal having a larger width than the seed crystal to be obtained.
Also, the non-patent literature discloses that the grown β-Ga2O3 single crystal is 75 seconds in full width at half maximum (FWHM) of x-ray rocking curve and 9×104 cm−2 in pit density.